Abstract

A series of eight novel proline functionalized dipeptide imidazolium ionic liquids (DPILs), i.e. Boc-[Pro-Pro-EMIM], Boc-[Pro-Val-EMIM], Boc-[Pro-Ala-EMIM], Boc-[Pro-Phe-EMIM] containing [Cl] and [NTf₂] anions were synthesized via a facile reaction of 2-chloroethylamine with four different dipeptides (Boc-Pro-Pro-OH, Boc-Pro-Val-OH, Boc-Pro-Ala-OH, and Boc-Pro-Phe-OH) followed by reaction with 1-methylimidazole and subsequent anion exchange. The synthesized ILs revealed similar characteristics of a conventional imidazolium ILs. The synthesized ILs were investigated by ¹H NMR, ¹³C NMR, FT-IR, mass spectroscopy, TGA, and DSC. TGA revealed an improved thermal stability for NTf₂ over chloride ion. DSC revealed a melting temperature less than 100 °C.

Graphic abstract

中文翻译：

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新型脯氨酸基咪唑鎓离子液体的合成

摘要

一系列八种新型脯氨酸功能化的二肽咪唑鎓离子液体（DPIL），即Boc- [Pro-Pro-EMIM]，Boc- [Pro-Val-EMIM]，Boc- [Pro-Ala-EMIM]，Boc- [Pro含有[Cl]和[NTf ₂ ]阴离子的-Phe-EMIM]是通过2-氯乙胺与四种不同的二肽（Boc-Pro-Pro-OH，Boc-Pro-Val-OH，Boc-Pro- Ala-OH和Boc-Pro-Phe-OH），然后与1-甲基咪唑反应，然后进行阴离子交换。合成的IL显示出与常规咪唑ILs相似的特征。通过¹ H NMR，¹³ C NMR，FT-IR，质谱，TGA和DSC研究合成的IL 。TGA显示NTf _2的热稳定性得到改善过氯离子。DSC显示熔融温度低于100℃。

图形摘要